If data are transmitted in a contactless and in particular in a wireless manner, e.g., via electromagnetic waves, interferences that can possibly even influence or change the transmitted data can be coupled in by noise or by crosstalk of other signals. For ensuring secure data transmission, it is known to transmit the data in a redundant manner, for example by transmitting, e.g., checksums together with the actual data. If the received data deviate from the checksum, obviously, an error has occurred during transmission. Here, the signals are transmitted from a transponder to a receiver or generally an apparatus for communicating with a transponder.
In conventional technology, it is known to provide objects with RFID transponders (RFID=radio frequency identification) or also RFID tags as an example of the above-stated transponders. RFID readers can read out identification data from the RFID transponders or data (for example measurement data) are transmitted from an object connected to the transponder (e.g., a measuring device or sensor) to the reader.
The more and more frequently used high-frequency RFID transponders of conventional technology are typically passive and are excited and activated, respectively, by a high-frequency electromagnetic field. Generally, these RFID transponders have only little energy or no individual energy resources at all. Thus, the transponder uses the transmit signal from the reader and transmits, in response to the excitation, a modulated signal back to the reader. In most cases, the modulated signal is a backscatter signal, so that the signal emitted by the transponder results from a modulation of the transmit signal of the reader received by the transponder with a data signal of the transponder. By means of the data signal, this response signal includes information from the transponder that can be evaluated by the reader.
Thus, data integrity, i.e., secure and error-free transmission of the data signal is to be ensured, if in RFID transponders, according to conventional technology, data originating from the transponder have to be transmitted in a redundant manner. However, the increased data volume is disadvantageous, in particular in the example of the RFID transponders having limited energy resources.